1. Field of the Invention
The present invention relates to a thread compound composition including a calcium sulfonate base for use with threaded connections, especially threaded connections used in oilfield tool joints, drill collars, drilling strings, casing, tubing, line pipe, flow lines and subsurface production tools and in other severe condition industrial applications.
More particularly, the present invention relates to a thread compound including a calcium sulfonate base, where the compound has reduced loss due to interaction with drilling fluids during drilling operations for use on any threaded connection, but especially on threaded connections that are subjected to continuous or periodic contact with fluid that tend to remove, erode, chemical attack or ablate the compound coating threaded connections used in the oilfield or the like.
2. Description of the Related Art
Drilling muds have changed significantly over the last couple years due to environmental pressures and drilling in more extreme environments each year. These changes have resulted in degradation of conventional grease carriers due to chemical incompatibility. Extensive analysis of these muds with thread compounds and research and development into grease thickeners have resulted in new thread compound designs that adhere effectively to the threaded connections, to not degel at elevated temperatures, higher pH levels and aid in the galling resistance and corrosion resistance of this new series of products.
Current and past technology has incorporated such grease thickeners as calcium acetate complex, lithium complex, lithium stearate, lithium 12-hydroxystearate, anhydrous and hydrous calcium soaps, sodium soaps, organophyllic clays and silica. The thickener was typically selected for reasons of economics, performance or marketing advantage. Use of the new technology thickener has not been utilized, largely due to the high expense and until recent times offered no improved performance over cost advantage.
Technological improvements in the formula and optimizing process variables has resulted in the development of a grease base and product line that has no melting point, so applicable in high temperature service, and pH stability. The pH of drilling mud is increased as oil well depths increase and temperatures rise. pH stability, therefore, is imperative.
In certain applications, thread compounds are subject to severe erosion, ablation, or other removal processes, e specially when the threaded connections are continuously, periodically or transiently exposed to fluid that tends to remove the compound via circulation velocity and chemical attack. Erosion or removal is a particularly troublesome problem in the oil industry. During drilling operations, the threaded connections are exposed on a routine base to drilling fluids, which include drilling muds and shavings from the drilling operations. These fluids and/or shavings tend to dissolve, erode or ablate the compound removing the protection of the compound and increasing the likelihood of damage to the threaded connections during the engaging and disengaging process required due to repetitive drill bit replacement.
Thus, there is a need for a threaded connection compound with superior resistance to removal from exposure to fluid such as drilling fluids so that threaded connections that are continuously, periodically or intermittently exposed to such fluid do not expose the threaded connection to potential damage or catastrophic failure.